Impact of sphingolipid synthesis inhibition on the drug susceptibility patterns of Trichophyton species

The well known dermatophyte infections caused by Trichophyton species are an ambiguous problem to treat using the present arsenal of antifungals. This study expounds on the effect of inhibition of sphingolipid pathway on Trichophyton growth. Findings from the drug susceptibility assays suggest sphingolipid inhibition severely restricts the growth of T. interdigitale and T. tonsurans. The observed synergistic effects of combinations of sphingolipid inhibitor and conventional drugs provide a promising treatment strategy against Trichophyton infection.

Revised ISHAM-ABPA working group clinical practice guidelines for diagnosing, classifying and treating allergic bronchopulmonary aspergillosis/mycoses

BACKGROUND

The International Society for Human and Animal Mycology (ISHAM) working group proposed recommendations for managing allergic bronchopulmonary aspergillosis (ABPA) a decade ago. There is a need to update these recommendations due to advances in diagnostics and therapeutics.

METHODS

An international expert group was convened to develop guidelines for managing ABPA (caused by Aspergillus spp.) and allergic bronchopulmonary mycosis (ABPM; caused by fungi other than Aspergillus spp.) in adults and children using a modified Delphi method (two online rounds and one in-person meeting). We defined consensus as ≥70% agreement or disagreement. The terms "recommend" and "suggest" are used when the consensus was ≥70% and <70%, respectively.

RESULTS

We recommend screening for A. fumigatus sensitisation using fungus-specific IgE in all newly diagnosed asthmatic adults at tertiary care but only difficult-to-treat asthmatic children. We recommend diagnosing ABPA in those with predisposing conditions or compatible clinico-radiological presentation, with a mandatory demonstration of fungal sensitisation and serum total IgE ≥500 IU·mL-1 and two of the following: fungal-specific IgG, peripheral blood eosinophilia or suggestive imaging. ABPM is considered in those with an ABPA-like presentation but normal A. fumigatus-IgE. Additionally, diagnosing ABPM requires repeated growth of the causative fungus from sputum. We do not routinely recommend treating asymptomatic ABPA patients. We recommend oral prednisolone or itraconazole monotherapy for treating acute ABPA (newly diagnosed or exacerbation), with prednisolone and itraconazole combination only for treating recurrent ABPA exacerbations. We have devised an objective multidimensional criterion to assess treatment response.

CONCLUSION

We have framed consensus guidelines for diagnosing, classifying and treating ABPA/M for patient care and research.

Opportunistic microsporidiosis unveiled by fine-needle aspiration cytology of cervical lymph node with literature review

Microsporidia are highly specialized obligate intracellular organisms closely related to fungi, traditionally linked to diarrheal diseases in acquired immunodeficiency syndrome patients. Over the past two decades, an increasing incidence of extraintestinal infections affecting various organ systems, especially in immunocompromised individuals, has been observed. The report presents a unique case of lymph node microsporidiosis in a 38-year-old male, positive for human immunodeficiency virus, with coinfections of hepatitis B and C. Fine-needle aspiration cytology (FNAC) from cervical lymph node yielded pus-like, necrotic material with periodic acid-Schiff stained smear uncovering small round to oval spores on microscopy suspicious for microsporidia. Based on polymerase chain reaction and sequencing done with aspiration material, the causative agent was identified as Vittaforma corneae. This rare encounter highlights the significance of recognizing unique morphological characteristics of infectious organisms and employing appropriate ancillary techniques for precise identification. The case underscores the crucial role of FNAC in diagnosing opportunistic infections involving the lymph nodes and the growing significance of molecular tests for specific pathogen confirmation.

Incidence and prevalence of chronic pulmonary aspergillosis in patients with post-tuberculosis lung abnormality: Results from a community survey in North India

BACKGROUND

Post-tuberculosis lung abnormality (PTLA) is the most common risk factor for developing chronic pulmonary aspergillosis (CPA). However, the prevalence and incidence of CPA in PTLA patients in India remain unknown.

OBJECTIVES

We aimed to ascertain the incidence and prevalence of CPA in subjects with PTLA.

METHODS

We identified a cohort of pulmonary tuberculosis who completed anti-tuberculosis therapy (ATT) before November 2019 from the records of the 12 tuberculosis treatment centers attached to the national program. We recorded the clinical and demographic details. We performed computed tomography (CT) of the chest and estimated serum A. fumigatus-specific IgG. We categorised subjects as PTLA with or without CPA using a composite of clinical, radiological, and microbiological features. We resurveyed the subjects at 6 months (or earlier) for the presence of new symptoms. We calculated the prevalence and the incidence rate (per 100-person years) of CPA.

RESULTS

We included 117 subjects with PTLA, with a median of 3 years after ATT completion. Eleven subjects had CPA in the initial survey, and one additional case developed CPA during the second survey. The prevalence of CPA in PTLA subjects was 10.3% (12/117). The total observation period was 286.7 person-years. The median (interquartile range) time to develop CPA after ATT completion was 12.5 (5-36.7) months. We found the CPA incidence rate (95% confidence interval) of 4.2 (1.8-6.5) per 100-person years.

CONCLUSION

Chronic pulmonary aspergillosis complicates 10% of PTLA subjects after successful outcomes with ATT. Four new CPA cases may develop per 100-persons years of observation after ATT completion. We suggest screening patients with PTLA who develop new symptoms for CPA.

Nucleic-Acid-Based Molecular Fungal Diagnostics: A Way to a Better Future

The world has seen a tremendous increase in the number of fungal infections during the past two decades. Recently, the World Health Organisation released the pathogen priority list for fungal infections, signifying the importance of these infections in the fields of research and public health. Microbiology laboratories demand an upgrade in the diagnostic system to keep up with the increased burden of these infections. Diagnosis of fungal infections using conventional techniques has always faced limitations in terms of specificity, sensitivity, and turnaround time. Although these methods are the core pillars of the diagnosis, there is an increased need for molecular approaches. Molecular techniques have revolutionised the field of fungal diagnostics. The diverse array of molecular techniques, including techniques like Polymerase Chain Reaction (PCR), have emerged as a cornerstone in fungal diagnostics. Molecular techniques have transformed fungal diagnostics, providing powerful tools for the rapid and accurate identification of pathogens. As these technologies continue to evolve, their integration into routine clinical practice holds the promise of improving patient outcomes through timely and targeted antifungal interventions. This review will cover the molecular approaches involved in fungal diagnostics, moving from the basic techniques to the advanced-level nucleic-acid-based molecular approaches providing a high throughput and decreased turnaround time for the diagnosis of serious fungal infections.

Polymorphisms in Innate and Adaptive Immune Genes in Subjects with Allergic Bronchopulmonary Aspergillosis Complicating Asthma

Innate and adaptive immunity play a crucial role in allergic bronchopulmonary aspergillosis (ABPA) pathogenesis. We performed next-generation sequencing using the Illumina TruSight One panel (4,811 human disease-associated genes, at least 20 × coverage) and selected 22 known immune genes (toll-like receptors (TLRs), C-type lectin, interleukin-4 receptor, and others). We included ABPA (n = 18), asthma without ABPA (n = 12), and healthy controls (n = 8). We analyzed 3011 SNPs from 22 genes and identified 145 SNPs (13 genes) that were present only in the disease groups and absent in controls. The SNP frequency overall was significantly higher in ABPA than in asthmatics (89/145 [61.4%] vs. 56/145 [38.6%], p = 0.0001). The SNP frequency in the TLR10 gene was also significantly higher in ABPA than in asthma (p = 0.017). Association analysis further revealed three genes having significant associations. Of these, NOS3 and HLA-DQB1 are associated with antimicrobial activity and adaptive immunity. More extensive studies are required to confirm our findings.

Sensitivity and specificity of LDBio Aspergillus ICT lateral flow assay for diagnosing allergic bronchopulmonary aspergillosis in adult asthmatics

BACKGROUND

Aspergillus fumigatus-specific IgG estimation is crucial for diagnosing allergic bronchopulmonary aspergillosis (ABPA). A point-of-care LDBio immunochromatographic lateral flow assay (LFA) had 0%-90% sensitivity to detect IgG/IgM antibodies against A. fumigatus.

OBJECTIVE

To assess the accuracy of LDBio-LFA in diagnosing ABPA, using the modified ISHAM-ABPA working group criteria as the reference standard. The secondary objective was to compare the diagnostic performance between LDBio-LFA and A. fumigatus-specific IgG (cut-offs, 27 and 40 mgA/L), using a multidisciplinary team (blinded to A. fumigatus-IgG and LDBio-LFA results) diagnosis of ABPA as the reference standard.

METHODS

We prospectively enrolled adult subjects with asthma and ABPA. We performed the LDBio-LFA per the manufacturer's recommendations. We used the commercially available automated fluorescent enzyme immunoassay for measuring serum A. fumigatus-specific IgG. We used the same serum sample to perform both index tests. The tests were performed by technicians blinded to the results of other tests and clinical diagnoses.

RESULTS

We included 123 asthmatic and 166 ABPA subjects, with a mean ± SD age of 37.4 ± 14.4 years. Bronchiectasis and high-attenuation mucus were seen in 93.6% (146/156) and 24.3% (38/156) of the ABPA subjects. The sensitivity and specificity of LDBio-LFA in diagnosing ABPA were 84.9% and 82.9%, respectively. The sensitivity of serum A. fumigatus-specific IgG ≥27 mgA/L was 13% better than LDBio-LFA, with no difference in specificity. There was no significant difference in sensitivity and specificity between LDBio-LFA and serum A. fumigatus-IgG ≥40 mgA/L.

CONCLUSION

LDBio-LFA is a valuable test for diagnosing ABPA. However, a negative test should be confirmed using an enzyme immunoassay.

A promising antifungal lipopeptide from Bacillus subtilis: its characterization and insight into the mode of action

Emerging resistance of fungal pathogens and challenges faced in drug development have prompted renewed investigations into novel antifungal lipopeptides. The antifungal lipopeptide AF3 reported here is a natural lipopeptide isolated and purified from Bacillus subtilis. The AF3 lipopeptide's secondary structure, functional groups, and the presence of amino acid residues typical of lipopeptides were determined by circular dichroism, Fourier transform infrared spectroscopy, and nuclear magnetic resonance spectroscopy. The lipopeptide's low minimum inhibitory concentrations (MICs) of 4-8 mg/L against several fungal strains demonstrate its strong antifungal activity. Biocompatibility assays showed that ~ 80% of mammalian cells remained viable at a 2 × MIC concentration of AF3. The treated Candida albicans cells examined by scanning electron microscopy, transmission electron microscopy, and atomic force microscopy clearly showed ultrastructural alterations such as the loss of the cell shape and cell membrane integrity. The antifungal effect of AF3 resulted in membrane permeabilization facilitating the uptake of the fluorescent dyes-acridine orange (AO)/propidium iodide (PI) and FUN-1. Using 1,6-diphenyl-1,3,5-hexatriene (DPH) and 4-(2-[6-(dioctylamino)-2-naphthalenyl] ethenyl)-1-(3-sulfopropyl) pyridinium inner salt (di-8-ANEPPS), we observed that the binding of AF3 to the membrane bilayer results in membrane disruption and depolarization. Flow cytometry analyses revealed a direct correlation between lipopeptide activity, membrane permeabilization (~ 75% PI uptake), and reduced cell viability. An increase in 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) fluorescence demonstrates endogenous reactive oxygen species production. Lipopeptide treatment appears to induce late-stage apoptosis and alterations to nuclear morphology, suggesting that AF3-induced membrane damage may lead to a cellular stress response. Taken together, this study illustrates antifungal lipopeptide's potential as an antifungal drug candidate. KEY POINTS: • The studied lipopeptide variant AF3 displayed potent antifungal activity against C. albicans • Its biological activity was stable to proteolysis • Analytical studies demonstrated that the lipopeptide is essentially membranotropic and able to cause membrane dysfunction, elevated ROS levels, apoptosis, and DNA damage.

Sphingolipid diversity in Candida auris: unraveling interclade and drug resistance fingerprints

In this study, we explored the sphingolipid (SL) landscape in Candida auris, which plays pivotal roles in fungal biology and drug susceptibility. The composition of SLs exhibited substantial variations at both the SL class and molecular species levels among clade isolates. Utilizing principal component analysis, we successfully differentiated the five clades based on their SL class composition. While phytoceramide (PCer) was uniformly the most abundant SL class in all the isolates, other classes showed significant variations. These variations were not limited to SL class level only as the proportion of different molecular species containing variable number of carbons in fatty acid chains also differed between the isolates. Also a comparative analysis revealed abundance of ceramides and glucosylceramides in fluconazole susceptible isolates. Furthermore, by comparing drug-resistant and susceptible isolates within clade IV, we uncovered significant intraclade differences in key SL classes such as high PCer and low long chain base (LCB) content in resistant strains, underscoring the impact of SL heterogeneity on drug resistance development in C. auris. These findings shed light on the multifaceted interplay between genomic diversity, SLs, and drug resistance in this emerging fungal pathogen.

Mucormycosis: Cytomorphological Spectrum in Fine-Needle Aspiration Cytology

Background

Mucormycosis is a fungal infection that can affect multiple organs. The role of fine-needle aspiration cytology (FNAC) in its diagnosis is not well documented.

Aim

The objective of this study was to describe the detailed cytomorphologic features of mucormycosis on FNAC samples.

Materials and Methods

A retrospective analysis of all cases diagnosed as mucormycosis on FNAC between January 2014 and July 2021 was performed for detailed cytomorphological evaluation and correlation to clinical data and microbiological studies wherever available. FNA was computed tomography-guided (n = 38), ultrasonography-guided (n = 31) or palpation-guided (n = 12), and slides were reviewed in two cases.

Results

A total of 83 cases of mucormycosis were evaluated. An immunocompromised setting was observed in 48 cases. The most common site of FNA was the lung (n = 57) followed by liver, soft tissue, palate, mediastinum, orbital/ocular region, and lymph node. Isolated renal involvement, a unique feature, was seen in seven cases. The aspirates were necrotic to pus-like or blood-mixed particulate. Broad, nonseptate, foldable, ribbon-like fungal hyphae showing right-angled branching were seen. The tissue reaction was predominantly necro-inflammatory (n = 36), bland necrotic (n = 22), mixed inflammatory (n = 16), suppurative (n = 5), necrotizing granulomatous (n = 3), and granulomatous (n = 1). Immunocompromised patients showed mixed inflammatory responses more frequently. Fungal culture was positive for Rhizopus species in 2/13 cases and molecular testing in two additional cases corresponding to Rhizopus and Syncephalastrum spp.

Conclusion

FNA provides quick and conclusive diagnosis of mucormycosis from varied anatomic sites enabling prompt institution of therapy. The tissue response is variable and to some extent dependent on the immune status of the patient.

Immune and metabolic perturbations in COVID-19-associated pulmonary mucormycosis: A transcriptome analysis of innate immune cells

BACKGROUND AND OBJECTIVES

The mechanisms underlying COVID-19-associated pulmonary mucormycosis (CAPM) remain unclear. We use a transcriptomic analysis of the innate immune cells to investigate the host immune and metabolic response pathways in patients with CAPM.

PATIENTS AND METHODS

We enrolled subjects with CAPM (n = 5), pulmonary mucormycosis (PM) without COVID-19 (n = 5), COVID-19 (without mucormycosis, n = 5), healthy controls (n = 5) without comorbid illness and negative for SARS-CoV-2. Peripheral blood samples from cases were collected before initiating antifungal therapy, and neutrophils and monocytes were isolated. RNA sequencing was performed using Illumina HiSeqX from monocytes and neutrophils. Raw reads were aligned with HISAT-2 pipeline and DESeq2 was used for differential gene expression. Gene ontology (GO) and metabolic pathway analysis were performed using Shiny GO application and R packages (ggplot2, Pathview).

RESULTS

The derangement of core immune and metabolic responses in CAPM patients was noted. Pattern recognition receptors, dectin-2, MCL, FcRγ receptors and CLEC-2, were upregulated, but signalling pathways such as JAK-STAT, IL-17 and CARD-9 were downregulated; mTOR and MAP-kinase signalling were elevated in monocytes from CAPM patients. The complement receptors, NETosis, and pro-inflammatory responses, such as S100A8/A9, lipocalin and MMP9, were elevated. The major metabolic pathways of glucose metabolism-glycolysis/gluconeogenesis, pentose phosphate pathway, HIF signalling and iron metabolism-ferroptosis were also upregulated in CAPM.

CONCLUSIONS

We identified significant alterations in the metabolic pathways possibly leading to cellular iron overload and a hyperglycaemic state. Immune responses revealed altered recognition, signalling, effector functions and a pro-inflammatory state in monocytes and neutrophils from CAPM patients.

Cladosporium halotolerans: Exploring an Unheeded Human Pathogen

BACKGROUND

Cladosporium halotolerans is a saprobic fungus, rarely implicated in human infections. The identification is challenging due to non-specific phenotypic features.

OBJECTIVE

To decipher clinical spectrum, microbiological and susceptibility profile of clinical and environmental isolates of Cladosporium halotolerans.

METHOD

All the isolates identified as Cladosporium halotolerans deposited in National Culture Collection for Pathogenic Fungi (NCCPF), Postgraduate Institute of Medical Education and Research, Chandigarh, India were revived. Phenotypic and molecular characterization targeting internal transcribed spacer (ITS) region of ribosomal DNA, large subunit of ribosomal DNA (LSU; NL1 and NL4), actin (ACT) and beta-tubulin (TUB) was done. Scanning electron microscopy (SEM) was performed to determine any phenotypic variations. Antifungal susceptibility testing (AFST) was carried out for eight antifungal agents as per CLSI M38 Ed3 guidelines. We also performed systematic literature review of all the cases of Cladosporium halotolerans reported till date.

RESULTS

A total of four isolates (clinical, n = 3; soil, n = 1) identified as Cladosporium halotolerans were included in the study. The clinical sites were skin, maxillary tissue and nail. All patients were apparently immunocompetent, and history of trauma was recorded in one patient. All patients improved on antifungal therapy. The cultures revealed growth of black mycelial fungus and microscopic examination demonstrated dematiaceous septate hyphae with erect conidiophores and conidia in branched acropetal chains. Based on molecular methods, all the four isolates were identified as C. halotolerans. SEM revealed no variation in length and width of the conidia, conidiophores, ramoconidium and hyphae among the isolates. All molecular targets, such as ITS region, LSU (partially sequenced), ACT and TUB were able to differentiate the isolates. Minimum inhibitory concentrations for antifungals were: triazoles (0.12-2 μg/ml), amphotericin B (4 μg/ml) and echinocandins (2-8 μg/ml).

CONCLUSION

We report role of the rarely isolated dematiaceous fungus, C. halotolerans, in causing human infections. The study emphasizes the role of molecular methods in precisely identifying these species. Triazoles are more active against these black fungi compared to polyenes or echinocandins.

Prevalence of Aspergillus sensitization and Allergic Bronchopulmonary Aspergillosis in bronchial asthma: A systematic review of Indian studies

Background

The prevalence of allergic bronchopulmonary aspergillosis (ABPA) in Indian asthmatic patients remains unknown. We systematically reviewed the literature for estimating the prevalence of Aspergillus sensitization (AS) and ABPA in Indian subjects with bronchial asthma.

Methods

We searched the PubMed and Embase databases for studies from India reporting the prevalence of AS or ABPA in at least 50 asthmatics. The primary outcome of our study was to assess the prevalence of ABPA. The secondary outcomes were to evaluate the prevalence of AS in asthma and ABPA in Aspergillus-sensitized asthma. We pooled the prevalence estimates using a random effects model and examined the factors influencing the prevalence using multivariate meta-regression.

Results

Of the 8,383 records retrieved, 34 studies with 14,580 asthmatics met the inclusion criteria. All the studies were from tertiary centers. The pooled prevalence of ABPA in asthmatics (26 studies; 5,554 asthmatics) was 16.2% [95% confidence interval (CI), 12.5-20.4]. The pooled prevalence of AS in asthma (29 studies; 13,405 asthmatics) was 30.9% (95% CI, 25.3-36.6), while the prevalence of ABPA in AS (20 studies; 1,493 asthmatics) was 48.2% (95% CI, 39.6-56.8). Meta-regression identified studies published after 2009 (OR 1.14; 95% CI, 1.02-1.28) and studies with severe asthmatics (OR 1.12; 95% CI, 1.00-1.26) as the only factors associated with higher ABPA prevalence.

Conclusions

There is a high prevalence of ABPA in Indian asthmatic subjects at tertiary centers, underscoring the need for screening all asthmatic subjects in special asthma and chest clinics for ABPA.

Scedosporium Infection in Recipients of Kidney Transplants from Deceased Near-Drowning Donor

Scedosporium aurianticum infection developed in 2 recipients of kidney transplants in India, acquired from the same deceased near-drowning donor. Given the substantial risk for death associated with Scedosporium infection among solid-organ transplant recipients, safety protocols for organ transplantation from nearly drowned donors should be thoroughly revaluated and refined.

Long-term follow-up of allergic bronchopulmonary aspergillosis treated with glucocorticoids: A study of 182 subjects

BACKGROUND

The long-term outcomes of allergic bronchopulmonary aspergillosis (ABPA) are poorly characterised.

METHODS

We retrospectively included treatment-naïve subjects of acute stage ABPA-complicating asthma from three randomised trials. All the subjects received oral prednisolone for 4 months and were monitored every 6 weeks for 6 months and then every 6 months. Our primary objective was to estimate the incidence rate and the frequency of subjects experiencing ABPA exacerbation. The key secondary objectives were to evaluate the factors predicting ABPA exacerbation and the changes in serum total IgE seen during treatment.

RESULTS

We included 182 subjects. Eighty-one (44.5%) patients experienced 120 exacerbations during 512 patient-years of follow-up. The incidence rate of ABPA exacerbations was 234/1000 patient-years. Most (73/81, 90.1%) subjects experienced ABPA exacerbation within three years of stopping therapy. On multivariate logistic regression analysis, peripheral blood eosinophil count ≥1000 cells/μL (adjusted odds ratio [aOR] 2.43; 95% confidence interval (CI), 1.26-4.67), the extent of bronchiectasis (aOR 1.10; 95% CI, 1.03-1.18), age (aOR 0.97; 95% CI, 0.94-0.99), and female sex (aOR 2.16; 95% CI, 1.10-4.24) independently predicted ABPA exacerbation after adjusting for serum total IgE and high-attenuation mucus. The best cut-off for serum total IgE after 6 weeks for identifying treatment response and ABPA exacerbations was a 20% decline and a 50% increase, respectively.

CONCLUSIONS

ABPA exacerbations were common within 3 years of stopping treatment. Age, female sex, peripheral blood eosinophilia and the extent of bronchiectasis predicted ABPA exacerbations. The optimal serum total IgE cut-off for defining ABPA response and exacerbations is a 20% decline and a 50% increase, respectively.

Role of C-Reactive Protein and Erythrocyte Sedimentation Rate in the Diagnosis and Monitoring of Treatment Response in Treatment Naïve Subjects with Chronic Pulmonary Aspergillosis

PURPOSE

The role of C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) for diagnosing chronic pulmonary aspergillosis (CPA) remains unknown. Herein, we investigate the diagnostic performance of serum ESR and CRP in CPA.

METHODS

We retrospectively analyzed the data of treatment-naïve subjects with CPA and diseased controls (post-tuberculosis lung disease on CT thorax). We treated CPA subjects with six months of oral itraconazole. Our primary objective was to evaluate the sensitivity and specificity of ESR and CRP in diagnosing CPA. The key secondary objective was to study the change in the inflammatory markers with treatment.

RESULTS

We included 434 subjects and 20 diseased controls. The sensitivity and specificity of ESR (n = 434) and CRP (at cut-off value of 10 mg/L, n = 308) in diagnosing CPA were 42.9% and 65%, and 52.3% and 65%, respectively. Both ESR and CRP had erratic trend following treatment. ESR and CRP declined or remained stable in approximately 60% of subjects but increased in approximately 40% of the subjects despite treatment.

CONCLUSION

Serum CRP and ESR have limited utility in diagnosing and following subjects with CPA.

Satellite Epidemic of Covid-19 Associated Mucormycosis in India: A Multi-Site Observational Study

BACKGROUND

Sudden upsurge in cases of COVID-19 Associated Mucormycosis (CAM) following the second wave of the COVID-19 pandemic was recorded in India. This study describes the clinical characteristics, management and outcomes of CAM cases, and factors associated with mortality.

METHODS

Microbiologically confirmed CAM cases were enrolled from April 2021 to September 2021 from ten diverse geographical locations in India. Data were collected using a structured questionnaire and entered into a web portal designed specifically for this investigation. Bivariate analyses and logistic regression were conducted using R version 4.0.2.

RESULTS

A total of 336 CAM patients were enrolled; the majority were male (n = 232, 69.1%), literate (n = 261, 77.7%), and employed (n = 224, 66.7%). The commonest presenting symptoms in our cohort of patients were oro-facial and ophthalmological in nature. The median (Interquartile Range; IQR) interval between COVID diagnosis and admission due to mucormycosis was 31 (18, 47) days, whereas the median duration of symptoms of CAM before hospitalization was 10 (5, 20) days. All CAM cases received antifungal treatment, and debridement (either surgical or endoscopic or both) was carried out in the majority of them (326, 97.02%). Twenty-three (6.9%) of the enrolled CAM cases expired. The odds of death in CAM patients increased with an increase in HbA1c level (aOR: 1.34, 95%CI: 1.05, 1.72) following adjustment for age, gender, education and employment status.

CONCLUSION

A longer vigil of around 4-6 weeks post-COVID-19 diagnosis is suggested for earlier diagnosis of CAM. Better glycemic control may avert mortality in admitted CAM cases.

Characterization of Treatment Response Outcomes in Chronic Pulmonary Aspergillosis: CPAnet Definitions Versus the Existing Criteria

BACKGROUND

The chronic pulmonary aspergillosis network (CPAnet) has recently proposed definitions for treatment outcomes in CPA. However, these definitions need to be validated. Herein, we evaluate the agreement between the existing and the CPAnet definitions for response assessment.

METHODS

We enrolled consecutive treatment-naïve CPA subjects (between January 2021 and June 2021) who received six months of itraconazole therapy and followed them for an additional six months after treatment discontinuation. We retrospectively applied the CPAnet criteria and compared the agreement between the existing and the CPAnet criteria for response assessment (primary objective). We also assessed if adding weight loss (> 5% from baseline) as a component improved the performance of the CPAnet criteria.

RESULTS

We included 43 (mean age, 47.4 years) CPA subjects. The existing and the CPAnet criteria categorized 29 (67.4%) and 30 (69.8%) subjects as treatment success, respectively, at treatment completion. There was substantial (kappa = 0.73; p < 0.0001) agreement between the two definitions. However, both criteria did not identify eight subjects requiring treatment re-initiation within three months. There was an increment in the sensitivity of both criteria (by 36%) for identifying treatment failure after incorporating ≥ 5% weight loss as an element of worsening.

CONCLUSION

The CPAnet definitions correctly categorized treatment outcomes in most cases of CPA. The addition of weight change would further enhance the performance of the CPAnet treatment outcome definitions.

Intergenic spacer (IGS-1) region sequence-based identification, genotypic analysis, and antifungal susceptibility of clinical Trichosporon species

OBJECTIVES

Molecular genotyping of Trichosporon species using intergenic spacer region (IGS-1) sequencing and antifungal drug susceptibility testing of T. asahii clinical isolates from Indian patients.

MATERIALS AND METHODS

Fifty-five Trichosporon strains were characterized using IGS-1 sequencing from 2006 to 2018 and tested against 5 antifungals using CLSI M27-A3 guidelines.

RESULTS

In this study, broad-spectrum antibiotics with steroids, catheters, and ICU stays were major underlying risk factors. These cases were most commonly associated with diabetes (type-2), chronic obstructive pulmonary disease, and hypertension. Out of fifty-five isolates, 47 (85%) were identified as T. asahii, and the remaining 6 were T. inkin (11%) and 2 were Cutaneotrichosporon dermatis (3.6%). The most common genotype of T. asahii was G3 (22; 49%) subsequently G4 (12; 23%), G1 (8; 17%), and G7 (2; 4%). One new genotype of T asahii was found in addition to the fifteen already known genotypes. Indian T. asahii isolates showed a low level of amphotericin B (range 0.06-4 ​mg/l) resistance but relatively higher in fluconazole (range 0.25-64 ​mg/l). Although, comparatively low MIC ranges were found in the case of voriconazole (0.03-1 ​mg/l), posaconazole (0.06-1 ​mg/l) and itraconazole (0.06-1 ​mg/l). Voriconazole appeared to be the most active drug in T. asahii isolates. The MICs for all the drugs were comparatively lower in the case of non-Trichosporon asahii strains.

CONCLUSION

T. asahii was the most common Trichosporon isolate. Speciation is necessary for optimal antifungal therapy. Voriconazole-based treatment, Steroids, removal of catheters and control of underlying conditions results in positive outcomes.

Onychomycosis caused by dematiaceous fungi: A four-year study on agricultural workers of Assam, India

Background and Purpose

Onychomycosis caused by dematiaceous fungi is rarely reported and the identification is also quite tricky due to poor sporulation. Recent emergence of dematiaceous fungi as a major cause of onychomycosis is a matter of concern in the field of mycology. Therefore, this study aimed to understand the dematiaceous fungi as a possible cause of onychomycosis, especially among agricultural workers. In addition, the evaluation of the antifungal susceptibility patterns led to the idea of an accurate drug that will help to treat and prevent antifungal resistance.

Materials and Methods

The standard procedure was followed for direct microscopic examination and fungi isolation. Furthermore, antifungal susceptibility testing was conducted in accordance with the Clinical and Laboratory Standards Institute M-38-A2 protocol.

Results

Both potassium hydroxide and fungal positivity were found in 275 out of 356 suspected cases, 52%, 4.3%, 28.7%, and 14.9% of which were non-dermatophytic molds (NDMs), yeast, dermatophytes, and sterile hyphae, respectively. Among NDMs (52%, n=143), 45.5% (n=65) were hyaline hyphomycetes and 54.5% (n=78) were dematiaceous hyphomycetes. Among dematiaceous fungi, Pestalotiopsis spp. and Arthrinium spp. were the commonly isolated ones. Additionally, azoles, amphotericin-B, and anidulafungin showed excellent antifungal activity against tested isolates.

Conclusion

Dematiaceous fungi are now becoming a potential cause of onychomycosis. A more detailed study is needed on the identification of these emerging isolates and the mode of action of antifungal drugs for a better treatment strategy.

Clinical and Mycologic Characteristics of Emerging Mucormycosis Agent Rhizopus homothallicus

We retrospectively reviewed consecutive cases of mucormycosis reported from a tertiary-care center in India to determine the clinical and mycologic characteristics of emerging Rhizopus homothallicus fungus. The objectives were ascertaining the proportion of R. homothallicus infection and the 30-day mortality rate in rhino-orbital mucormycosis attributable to R. homothallicus compared with R. arrhizus. R. homothallicus accounted for 43 (6.8%) of the 631 cases of mucormycosis. R. homothallicus infection was independently associated with better survival (odds ratio [OR] 0.08 [95% CI 0.02-0.36]; p = 0.001) than for R. arrhizus infection (4/41 [9.8%] vs. 104/266 [39.1%]) after adjusting for age, intracranial involvement, and surgery. We also performed antifungal-susceptibility testing, which indicated a low range of MICs for R. homothallicus against the commonly used antifungals (amphotericin B [0.03-16], itraconazole [0.03-16], posaconazole [0.03-8], and isavuconazole [0.03-16]). 18S gene sequencing and amplified length polymorphism analysis revealed distinct clustering of R. homothallicus.

Development of single-tube real-time PCR assay for the rapid detection of Aspergillus and Fusarium-The two most common causative agents in fungal keratitis

BACKGROUND

To compare the performance of conventional, semi-nested and real-time panfungal ITS PCRs for diagnosing fungal keratitis (FK) and develop genus-specific real-time PCR for the most common aetiology of FK.

METHODS

This multicentric study includes 232 corneal samples from suspected FK patients from four centres across India between November 2019 through August 2021. A total of 87 corneal buttons were included for the comparison of conventional, semi-nested and real-time ITS PCRs, of which 68 were from confirmed FK patients. Of these 87 samples, 44 (microscopy and culture positive for Aspergillus sp. and/or Fusarium sp.) were used for the standardisation of genus-specific real-time primers/probes. Subsequently, the best method showing highest sensitivity and specificity was validated in 188 samples.

RESULTS

On Bayesian comparison, conventional ITS2 PCR showed best performance (sensitivity and specificity of 55.88% and 100%, respectively). Since, real-time ITS2 PCR was also considerably efficient (sensitivity and specificity of 51.47% and 84.21%, respectively) in comparison with the conventional PCR but faster, cost-effective, and less labor-intensive, ITS-2 real-time PCR is a suitable method that can be applied along with culture and microscopy. During validation, real-time PCR with genus-specific primers showed 61.76% and 91.18% sensitivity with specificity of 98.05% and 79.22%, respectively, for Aspergillus sp. and Fusarium sp. Aspergillus probe, Fusarium probe and duplex PCR showed sensitivity of 52.94%, 50% and 54.41% with specificity of 92.86%, 82.47% and 75%, respectively. No cross-reactivity of genus-specific PCRs was observed during standardisation.

CONCLUSIONS

ITS-2 real-time PCR can be applied as an adjunct with conventional methods for the diagnosis of FK. The genus-specific duplex real-time PCRs are rapid which reduces the turnaround time (TAT) avoiding the need for sequencing.

Application of Novel Short Tandem Repeat Typing for Wickerhamomyces anomalus Reveals Simultaneous Outbreaks within a Single Hospital

Wickerhamomyces anomalus, previously known as Candida pelliculosa, occasionally causes candidemia in humans, primarily infecting neonates, and infants. The mortality rate of these invasive infections is high, and isolates with a reduced susceptibility to fluconazole have been reported. W. anomalus outbreaks are regularly reported in healthcare facilities, especially in neonatal intensive care units (NICUs). In order to rapidly genotype isolates with a high-resolution, we developed and applied a short tandem repeat (STR) typing scheme for W. anomalus. Six STR markers were selected and amplified in two multiplex PCRs, M3 and M6, respectively. In total, 90 W. anomalus isolates were typed, leading to the identification of 38 different genotypes. Four large clusters were found, unveiling simultaneous outbreak events spread across multiple units within the same hospital. STR typing results of 11 isolates were compared to whole-genome sequencing (WGS) single nucleotide polymorphism (SNP) calling, and the identified genotypic relationships were highly concordant. We performed antifungal susceptibility testing of these isolates, and a reduced susceptibility to fluconazole was found for two (2.3%) isolates. ERG11 genes of these two isolates were examined using WGS data, which revealed a novel I469L substitution in one isolate. By constructing a homology model for W. anomalus ERG11p, the substitution was found in close proximity to the fluconazole binding site. In summary, we showed multiple W. anomalus outbreak events by applying a novel STR genotyping scheme.

Nebulized amphotericin B for preventing exacerbations in allergic bronchopulmonary aspergillosis: A systematic review and meta-analysis

BACKGROUND

Allergic bronchopulmonary aspergillosis (ABPA) is complicated by exacerbations in more than one-third of the subjects. Whether nebulized amphotericin B (NAB) therapy prevents ABPA exacerbations remains unclear.

OBJECTIVES

The primary objective of this systematic review and meta-analysis was to determine the frequency of subjects remaining exacerbation-free, one year after initiating NAB. The key secondary objectives were the time to first exacerbation and the safety of NAB therapy.

METHODS

We searched the PubMed and Embase databases for studies evaluating ≥5 subjects of ABPA managed with NAB. We report the pooled proportion of ABPA subjects remaining exacerbation free after one year. For the randomized controlled trials (RCTs), we estimate the pooled risk difference (RD) of exacerbation-free status at one year with NAB versus the control arm.

RESULTS

We included five studies for our analysis; three were observational (n = 28) and two RCTs (n = 160). The pooled proportion (95% confidence interval [CI]) of subjects remaining exacerbation free with NAB at one year was 76% (62-88). The pooled RD (95% CI) of an exacerbation-free status at one year was 0.33 (-0.12 to 0.78) and was not significantly different between the NAB and control arms. The time to first exacerbation was longer with NAB than with the standard therapy. No serious adverse events were reported with NAB.

CONCLUSION

NAB does not improve exacerbation-free status at one year; however, weak evidence suggests it delays ABPA exacerbations. More research using different dosing regimens is required.

Comprehensive Taxonomical Analysis of Trichophyton mentagrophytes/interdigitale Complex of Human and Animal Origin from India

Taxonomic delineation of etiologic agents responsible for recalcitrant dermatophytosis causing an epidemic in India is still debated. The organism responsible for this epidemic is designated as T. indotineae, a clonal offshoot of T. mentagrophytes. To evaluate the real identity of the agent causing this epidemic, we performed a multigene sequence analysis of Trichophyton species isolated from human and animal origin. We included Trichophyton species isolated from 213 human and six animal hosts. Internal transcribed spacer (ITS) (n = 219), translational elongation factors (TEF 1-α) (n = 40), ß-tubulin (BT) (n = 40), large ribosomal subunit (LSU) (n = 34), calmodulin (CAL) (n = 29), high mobility group (HMG) transcription factor gene (n = 17) and α-box gene (n = 17) were sequenced. Our sequences were compared with Trichophyton mentagrophytes species complex sequences in the NCBI database. Except for one isolate (ITS genotype III) from animal origin, all the tested genes grouped our isolates and belonged to the "Indian ITS genotype", currently labeled as T. indotineae. ITS and TEF 1-α were more congruent compared to other genes. In this study, for the first time, we isolated the T mentagrophytes ITS Type VIII from animal origin, suggesting the role of zoonotic transmission in the ongoing epidemic. Isolation of T. mentagrophytes type III only from animal indicates its niche among animals. Outdated/inaccurate naming for these dermatophytes in the public database has created confusion in using appropriate species designation.

The minimal important difference of St.George's respiratory questionnaire in subjects with chronic pulmonary aspergillosis

The estimates of the minimal important difference (MID) for the Saint George's respiratory questionnaire (SGRQ) score in CPA remain unknown. We performed a retrospective analysis on treatment-naïve CPA subjects (n = 148) treated with six-month oral itraconazole therapy and completed SGRQ at baseline and six months. The study's objective was to estimate the MID for SGRQ. We used an anchor-based method to determine the MID and found the MID for SGRQ of 7.3.

Aspergillosis: an Update on Clinical Spectrum, Diagnostic Schemes, and Management

Purpose of Review

This review gives an overview of the diseases caused by Aspergillus, including a description of the species involved and the infected clinical systems. We provide insight into the various diagnostic methods available for diagnosing aspergillosis, particularly invasive aspergillosis (IA), including the role of radiology, bronchoscopy, culture, and non-culture-based microbiological methods. We also discuss the available diagnostic algorithms for the different disease conditions. This review also summarizes the main aspects of managing infections due to Aspergillus spp., such as antifungal resistance, choice of antifungals, therapeutic drug monitoring, and new antifungal alternatives.

Recent Findings

The risk factors for this infection continue to evolve with the development of many biological agents that target the immune system and the increase of viral illnesses such as coronavirus disease. Due to the limitations of present mycological test methods, establishing a fast diagnosis is frequently difficult, and reports of developing antifungal resistance further complicate the management of aspergillosis. Many commercial assays, like AsperGenius®, MycAssay Aspergillus®, and MycoGENIE®, have the advantage of better species-level identification and concomitant resistance-associated mutations. Fosmanogepix, ibrexafungerp, rezafungin, and olorofim are newer antifungal agents in the pipeline exhibiting remarkable activity against Aspergillus spp.

Summary

The fungus Aspergillus is found ubiquitously around the world and can cause various infections, from harmless saprophytic colonization to severe IA. Understanding the diagnostic criteria to be used in different patient groups and the local epidemiological data and antifungal susceptibility profile is critical for optimal patient management.

Saksenaea vasiformis infection: Extensive abdominal wall necrotizing fasciitis with systematic review and analysis of 65 cases

INTRODUCTION

Saksenaea vasiformis is a rarely reported Mucorales causing mucormycosis in both immunocompromised and immunocompetent individuals. Due to few reported cases, the clinical characteristics and optimal management strategy for this rare agent are not clearly described.

METHODS

We systematically reviewed Medline, EmBase and CINHAL for studies on S. vasiformis infections reported until 1 January 2022 and 57 studies (63 patients) were retrieved. Additionally, one more case of extensive abdominal wall necrotizing fasciitis managed by our team was also included. The clinical and demographic characteristics and outcomes were extracted and analysed.

RESULTS

Out of the 65 included cases, the majority were reported from India (26.6%). The most common risk factors for infection were accidental trauma wounds (31.3%), health-care-related wounds (14.1%) and animal/insect bites (12.5%). Most common clinical presentation was subcutaneous mucormycosis (60.9%) followed by rhino-orbito cerebral mucormycosis (14%), necrotizing fasciitis (10%), disseminated infection (9.3%), pulmonary mucormycosis (3.2%) and osteomyelitis (1.6%). Mortality was observed in 24 (37.5%) patients and health care related injuries were significantly associated with higher mortality (p = .001). The use of posaconazole (p = .019) and the use of surgical management (p = .032) was associated with significantly better survival.

DISCUSSION

In this study, we describe the largest compendium of mucormycosis due to S. vasiformis, which can be useful in increasing awareness regarding this rare Mucorales and guiding patient management.

Correlation of plasma levels of itraconazole with treatment response at 4 weeks in chronic dermatophytosis: Results of a randomised controlled trial

BACKGROUND

Itraconazole in varying doses and duration is being frequently used for the management of dermatophytosis. There is a scarcity of studies on the bioavailability of various itraconazole brands available in the market.

AIMS AND OBJECTIVES

The aim of this study was to determine the plasma concentration of itraconazole of various brands and its correlation with clinical efficacy in chronic dermatophytosis.

MATERIALS AND METHODS

One hundred patients with chronic dermatophytosis with age >18 years were studied at the outpatient clinic of our tertiary care hospital. Plasma itraconazole level was estimated on Week 2 and Week 4 after randomly dividing the patients into Groups A, B and C who received cap itraconazole 100 mg twice a day of innovator, multinational and local generic brands, respectively, for 4 weeks. Both efficacy (cure, partial cure or no cure), safety and recurrence were compared between the three groups.

RESULTS

At 4 weeks, number of patients classified as 'cured' were 10/26 (38.4%) in Group A, 5/22 in Group B (22.7%) and 3/21 (14.2%) in Group C (p = .002). Mycological cure rates at Week 4 in Groups A, B and C were 21 (80.8%), 17 (81.0%) and 5 (26.3%), respectively (p = .006). Plasma levels of itraconazole were comparable between the three groups at Week 2 and Week 4. No statistically significant correlation was found between itraconazole levels and treatment response in any of the groups at 4 weeks. Incidence of adverse effects and recurrence rates was also similar among the three groups.

CONCLUSION

Cure rates for chronic dermatophytosis were poor with all three itraconazole brands at 4 weeks of treatment. Higher cure rates were obtained with innovator drug as compared to multinational and local generic brands at 4 weeks. Plasma levels of the three drugs were however similar, indicating that factors other than serum bioavailability are at play in determining response of chronic dermatophyte infections to oral itraconazole.

Identification of distinct immunophenotypes in chronic pulmonary aspergillosis using cluster analysis

BACKGROUND

Whether chronic pulmonary aspergillosis (CPA) has different immunophenotypes remains unknown.

OBJECTIVE

To identify different CPA immunophenotypes using cluster analysis.

METHODS

We used a subject-centred multivariate clustering approach without prior assumptions to identify CPA phenotypes. We retrospectively included the data of treatment-naïve subjects with CPA and excluded subjects with asthma and allergic bronchopulmonary aspergillosis (ABPA). We performed a scalable two-step cluster analysis using the log-likelihood distance measures to identify CPA phenotypes based on the blood immunological profile (total IgE, eosinophil count and Aspergillus-specific IgE and IgG).

RESULTS

We included 351 CPA subjects and found two clusters. Cluster 2 (n = 118) had significantly higher serum total IgE, peripheral blood eosinophil count, and serum A. fumigatus-specific IgE and IgG than cluster 1 (n = 233). Cluster 2 subjects had a lower FEV1:FVC ratio on spirometry and were more likely to have a fungal ball (88 [74.6%] vs. 145 (62.2%), p = .023) on the CT thorax than cluster 1. After treatment discontinuation, cluster 2 had a longer median (interquartile range) time to relapse than cluster 1 (11.5 [7.3-27.4] vs. 4 [1.1-8.9] months, p = .005).

CONCLUSION

We identified two distinct CPA phenotypes, type-2 dominant and non-type-2, with different clinical and radiological findings and treatment outcomes. Future studies should confirm our findings and investigate different treatment strategies based on CPA phenotypes.

Role of serum procalcitonin in the diagnosis and monitoring of treatment response in treatment-naïve subjects with chronic pulmonary aspergillosis

Background

Interferon-gamma (IFN-γ) down-regulates plasma procalcitonin (PCT), marker of inflammation. Chronic pulmonary aspergillosis (CPA) is associated with low IFN-γ levels. Thus, plasma PCT may be elevated in CPA and could have a role in diagnosing and monitoring treatment response in CPA. Herein, we investigate the diagnostic performance of plasma PCT in CPA.

Methods

We extracted the demographic, clinical, radiological, treatment outcomes, and plasma PCT levels of CPA subjects and controls (previously treated pulmonary tuberculosis with radiological abnormalities on CT chest [diseased controls] and treatment naïve active pulmonary tuberculosis [PTB]). We treated CPA subjects with six months of oral itraconazole. We took 0.25 ng/mL as a cut-off value for PCT. The study's primary objective was to ascertain the diagnostic performance of PCT in diagnosing CPA. The key secondary outcome was to study the change in the plasma PCT levels after itraconazole therapy.

Results

We included 190 CPA cases and 40 controls (diseased controls [n = 20] and active PTB [n = 20]). PCT was elevated (≥0.25 ng/mL) in only 7 (3.7%) subjects with CPA. The sensitivity and specificity of PCT (≥0.25 ng/mL) were 3.7% (1.5-7.4%) and 100 (91.2-100%), respectively. The area under the curve for plasma PCT was 0.48 (95% confidence interval, 0.39-0.58). The plasma PCT values were available in 93 subjects at six months. There was a significant decline in the median plasma levels of PCT after treatment; however, the PCT levels either increased or remained the same in 45% of the subjects.

Conclusion

Plasma procalcitonin has poor performance in diagnosing and following subjects with CPA.

Molecular epidemiology of Trichophyton infections among canines from Northern India

Dermatophytes are keratinophilic fungi that cause skin infections in both humans and animals. Recently, the incidence rates of fungal infections associated with Trichophyton spp. have been considered endemic in many locations. The aim of this study was to isolate and characterize Trichophyton spp. from canines and felines. In the present study, screened 442 canine (n = 386) and feline (n = 56) samples for dermatophytes. Among all the samples, ten isolates were identified as Trichophyton spp. based on micro-morphological features. For comparative analysis, we included three human strains of Trichophyton mentagrophytes complex. In vitro susceptibility of antifungal drugs indicated the highest sensitivity except for fluconazole. The canine and human strains were genetically characterized by sequencing three genes: the internal transcribed spacer region of rDNA, translation elongation factor 1- gene, and beta-tubulin. Based on sequence homology and phylogenetic analysis, the ten canine strains belonged to four different species/ genotypes such as T. mentagrophytes genotype VIII (T. indotineae) (n = 5), T. interdigitale (n = 2), T. simii (n = 2) and T. quinckeanum (n = 1). The three human strains used for comparative analysis were identified as T. mentagrophytes genotype VIII (n = 2) and T. benhamiae (n = 1). The study hence indicates that the T. mentagrophytes genotype VIII, considered as an endemic and emerging human pathogenic clone in India, is also the prevalent in animals.

Synthetic amino acids-based short amphipathic peptides exhibit antifungal activity by targeting cell membrane disruption

Availability of a limited number of antifungal drugs created a necessity to develop new antifungals with distinct mode of action. Investigation on a new series of peptides led us to identify Boc-His-Trp-His[1-(4-tert-butylphenyl)] (10g) as the most promising inhibitor exhibiting IC₅₀ value of 4.4 µg/mL against Cryptococcus neoformans. Analog 10g exhibit high selectivity to fungal cells and was nonhemolytic and noncytotoxic at its minimum inhibitory concentration. 10g produced fungicidal effect on growing cryptococcal cells and displayed synergistic effect with amphotericin B. Overall cationic character of 10g resulted in interaction with negatively charged fungal membrane while hydrophobicity enhanced penetration inside the cryptococcal cells causing hole(s) formation and disruption to the membrane as evident by the scanning electron microscopy, transmission electron microscopy, and confocal laser scanning microscopy analyses. Flow cytometric investigation revealed rapid death of fungal cells by apopotic pathway.

Functional Characterization of a Bacillus-Derived Novel Broad-Spectrum Antifungal Lipopeptide Variant against Candida tropicalis and Candida auris and Unravelling Its Mode of Action

Limited treatment options, recalcitrance, and resistance to existing therapeutics encourage the discovery of novel antifungal leads for alternative therapeutics. Antifungal lipopeptides have emerged as potential candidates for developing new and alternative antifungal therapies. In our previous studies, we isolated and identified the lipopeptide variant AF4 and purified it to homogeneity via chromatography from the cell-free supernatant of Bacillus subtilis. AF4 was found to have broad-spectrum antifungal activity against more than 110 fungal isolates. In this study, we found that clinical isolates of Candida tropicalis and Candida auris exposed to AF4 exhibited low MICs of 4 to 8 mg/L. Time-kill assays indicated the in vitro pharmacodynamic potential of AF4. Biocompatibility assays demonstrated ~75% cell viability at 8 mg/L of AF4, indicating the lipopeptide's minimally cytotoxic nature. In lipopeptide-treated C. tropicalis and C. auris cells, scanning electron microscopy revealed damage to the cell surface, while confocal microscopy with acridine orange(AO)/propidium iodide (PI) and FUN-1 indicated permeabilization of the cell membrane, and DNA damage upon DAPI (4',6-diamidino-2-phenylindole) staining. These observations were corroborated using flow cytometry (FC) in which propidium iodide, 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA), and rhodamine 123 (Rh123) staining of cells treated with AF4 revealed loss of membrane integrity, increased reactive oxygen species (ROS) production, and mitochondrial membrane dysfunction, respectively. Membrane perturbation was also observed in the 1,6-diphenyl-1,3,5-hexatriene (DPH) fluorescence study and the interaction with ergosterol was observed by an ergosterol binding assay. Decreased membrane dipole potential also indicated the probable binding of lipopeptide to the cell membrane. Collectively, these findings describe the mode of action of AF4 against fungal isolates by membrane disruption and ROS generation, demonstrating its antifungal potency. IMPORTANCE C. tropicalis is a major concern for candidiasis in India and C. auris has emerged as a resistant yeast causing difficult-to-treat infections. Currently, amphotericin B (AMB) and 5-flucytosine (5-FC) are the main therapeutics for systemic fungal infections; however, the nephrotoxicity of AMB and resistance to 5-FC is a serious concern. Antifungal lead molecules with low adverse effects are the need of the hour. In this study, we briefly describe the antifungal potential of the AF4 lipopeptide and its mode of action using microscopy, flow cytometry, and fluorescence-based assays. Our investigation reveals the basic mode of action of the investigated lipopeptide. This lipopeptide with broad-spectrum antifungal potency is apparently membrane-active, and there is a smaller chance that organisms exposed to such a compound will develop drug resistance. It could potentially act as a lead molecule for the development of an alternative antifungal agent to combat candidiasis.

Anticryptococcal activity and mechanistic studies of short amphipathic peptides

Cryptococcus neoformans, an opportunistic fungal pathogen, causes cryptococcosis in immunocompromised persons. A series of modified L-histidines-containing peptides are synthesized that exhibit promising activity against C. neoformans. Analog 11d [L-His(2-adamantyl)-L-Trp-L-His(2-phenyl)-OMe] produced potency with an IC₅₀ of 3.02 µg/ml (MIC = 5.49 µg/ml). This peptide is noncytotoxic and nonhaemolytic at the MIC and displays synergistic effects with amphotericin B at subinhibitory concentration. Mechanistic investigation of 11d using microscopic tools indicates cell wall and membrane disruption of C. neoformans, while flow cytometric analysis confirms cell death by apoptosis. This study indicates that 11d exhibits antifungal potential and acts via the rapid onset of action.

Disseminated Cryptococcosis and Pulmonary Mucormycosis: Dealing with Dual Mycoses in a Renal Transplant Patient

We describe a 36-year-old post-renal transplant patient diagnosed with a rare dual infection by Cryptococcus neoformans and Lichtheimia ramosa. The case highlights the significance of invasive samples and accurate interpretation of fungal biomarkers in the diagnosis of fungal infections in immunosuppressed patients. The mortality in such cases is high owing to delay in diagnosis, inability to perform surgical management or antifungal resistance.

Ring-Modified Histidine-Containing Cationic Short Peptides Exhibit Anticryptococcal Activity by Cellular Disruption

Delineation of clinical complications secondary to fungal infections, such as cryptococcal meningitis, and the concurrent emergence of multidrug resistance in large population subsets necessitates the need for the development of new classes of antifungals. Herein, we report a series of ring-modified histidine-containing short cationic peptides exhibiting anticryptococcal activity via membrane lysis. The N-1 position of histidine was benzylated, followed by iodination at the C-5 position via electrophilic iodination, and the dipeptides were obtained after coupling with tryptophan. In vitro analysis revealed that peptides Trp-His[1-(3,5-di-tert-butylbenzyl)-5-iodo]-OMe (10d, IC₅₀ = 2.20 μg/mL; MIC = 4.01 μg/mL) and Trp-His[1-(2-iodophenyl)-5-iodo)]-OMe (10o, IC₅₀ = 2.52 μg/mL; MIC = 4.59 μg/mL) exhibit promising antifungal activities against C. neoformans. When administered in combination with standard drug amphotericin B (Amp B), a significant synergism was observed, with 4- to 16-fold increase in the potencies of both peptides and Amp B. Electron microscopy analysis with SEM and TEM showed that the dipeptides primarily act via membrane disruption, leading to pore formation and causing cell lysis. After entering the cells, the peptides interact with the intracellular components as demonstrated by confocal laser scanning microscopy (CLSM).

Trend of pediatric cryptococcosis in a tertiary care centre and review of literature

PURPOSE

Cryptococcosis is one of the most significant systemic fungal infections worldwide. Epidemiological data for pediatric cryptococcosis is very limited. Therefore, we planned this study to determine the burden of cryptococcosis in the pediatric population at our tertiary care center and performed review of literature.

MATERIAL AND METHODS

In this retrospective study, all the patients less than 18 years of age were diagnosed with cryptococcosis, from January 2015-June 2021 were included. Demographic, clinical, and laboratory details of all the patients were noted. Furthermore, PubMed and MedLine databases were comprehensively searched for cases of pediatric cryptococcosis till June 2021.

RESULTS

Of the total 5420 samples from suspected cryptococcosis cases processed at mycology laboratory, a total of 21 episodes of cryptococcosis (0.39%) were identified in 15 pediatric patients. The majority of the patients were apparently immunocompetent (10/15). Central nervous system (CNS) cryptococcosis was the most common presentation, followed by disseminated disease. All the isolates were identified as Cryptococcus neoformans (formerly referred to as C. neoformans var grubii), except one that was identified as Papiliotrema laurentii (formerly referred to as Cryptococcus laurentii). A standard treatment regimen inclusive of induction and maintenance therapy was provided in only five patients. The literature review revealed a total of 125 studies describing 1134 cases, of which 76.4% are reported from outside Asia, the majority (65.7%) restricted to CNS with C. neoformans as the commonest species. The management profile divulged a significantly higher use of standard drug regimen in Asia as compared to the rest of the world. Mortality of 13.32% was noted worldwide.

CONCLUSION

To the best of our knowledge, this is the first clinico-epidemiological study of pediatric cryptococcosis from India and the largest retrospective study worldwide. The rising incidence among immunocompetent individuals, especially in Asia, is a matter of concern. Clinical suspicion and early diagnosis are the cornerstones for the management of cases.

A case control investigation of COVID-19 associated mucormycosis in India

Background

Increased occurrence of mucormycosis during the second wave of COVID-19 pandemic in early 2021 in India prompted us to undertake a multi-site case–control investigation. The objectives were to examine the monthly trend of COVID-19 Associated Mucormycosis (CAM) cases among in-patients and to identify factors associated with development of CAM.

Methods

Eleven study sites were involved across India; archived records since 1st January 2021 till 30th September 2021 were used for trend analysis. The cases and controls were enrolled during 15th June 2021 to 30th September 2021. Data were collected using a semi-structured questionnaire. Among 1211 enrolled participants, 336 were CAM cases and 875 were COVID-19 positive non-mucormycosis controls.

Results

CAM-case admissions reached their peak in May 2021 like a satellite epidemic after a month of in-patient admission peak recorded due to COVID-19. The odds of developing CAM increased with the history of working in a dusty environment (adjusted odds ratio; aOR 3.24, 95% CI 1.34, 7.82), diabetes mellitus (aOR: 31.83, 95% CI 13.96, 72.63), longer duration of hospital stay (aOR: 1.06, 95% CI 1.02, 1.11) and use of methylprednisolone (aOR: 2.71, 95% CI 1.37, 5.37) following adjustment for age, gender, occupation, education, type of houses used for living, requirement of ventilatory support and route of steroid administration. Higher proportion of CAM cases required supplemental oxygen compared to the controls; use of non-rebreather mask (NRBM) was associated as a protective factor against mucormycosis compared to face masks (aOR: 0.18, 95% CI 0.08, 0.41). Genomic sequencing of archived respiratory samples revealed similar occurrences of Delta and Delta derivates of SARS-CoV-2 infection in both cases and controls.

Conclusions

Appropriate management of hyperglycemia, judicious use of steroids and use of NRBM during oxygen supplementation among COVID-19 patients have the potential to reduce the risk of occurrence of mucormycosis. Avoiding exposure to dusty environment would add to such prevention efforts.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07844-y.

Epidemiology of Invasive Fungal Infections in Solid Organ Transplant Recipients: an Indian Perspective

Purpose of Review

This review summarizes the available Indian data on epidemiology of invasive fungal infections (IFI) in recipients of solid organ transplants (SOT). The epidemiology is further compared with studies from other parts of the world for each SOT type.

Recent Findings

The available studies on Indian epidemiology of IFI in SOT are scarce, though the number of SOTs performed in India have increased tremendously in recent years. The limited data from India present a distinct spectrum of infection in transplant recipients with high incidence of mucormycosis. During COVID-19 outbreak, IFI rate increased and renal transplant recipients acquired mucormycosis earlier than previous studies.

Summary

Maximum data on IFI was available from renal transplant recipients, wherein mucormycosis was the predominant IFI in Indian patients in contrast to invasive candidiasis in majority countries. The other IFIs had varied spectrum. With the increasing number of SOTs being performed and the already persisting high burden of IFI in India, there is an urgent need of larger prospective studies on epidemiology of IFI in transplant recipients.

Initial Case Report of Cladorrhinum samala Mycotic Keratitis

PURPOSE

The purpose of this study was to report the first case of keratitis caused by Cladorrhinum samala and review of the literature.

METHODS

This was a case report and literature review.

RESULTS

A 35-year-old immunocompetent man presented with pain, redness, and watering in the right eye 7 days after trauma with some foreign body. He was diagnosed with infectious keratitis, and a thorough microbiological workup was performed. Corneal scrapings were subjected to a potassium hydroxide (KOH) examination, Gram staining, bacterial (blood agar and Robertson cooked meat broth), and fungal culture (Sabouraud dextrose agar and brain-heart infusion agar). The KOH mount revealed septate fungal hyphae with irregular margins. Yellow-white nonsporulating mycelial growth was noted on the Sabouraud dextrose agar, which was identified as C. samala by sequencing. The patient responded to 5% natamycin and 1% voriconazole eye drops, and there was a formation of a corneal opacity in a period of 3 weeks.

CONCLUSIONS

We report the first case of keratitis by C. samala, highlighting the emergence of a rare dematiaceous fungi causing keratitis and the role of molecular modalities in the diagnosis of nonsporulating fungi in suspected cases.